Improvement in rotary blowers



@uiten grains @anni @fnf` Letters Patent No. 82,736, ma october 6, i868.

IMPROVEMENT IN ROTARY BLOWERS.

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TO ALL WHOM IT MAY CONGERN: Y

:Be it known that I, JAMES MITCHELL, of Philadelphia, rin the county of Philadelphia, and State of Pennsylvania, have invented a new and improved Ro'tary Fan or Blower; and'I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, which are made a part of this specification.

Figure 1 representsa transverse section at x z, fig. 2, of a rotary fan illustrating my invention.

Figure 2 is a longitudinal section thereof at y y, iig. 1.

Similar letters of reference indicate corresponding parts in both views.

The object of my invention is to increase the blowing-capacity of a rotary fan, and-this I accomplish by providing an auxiliary air-passage, so located within the fan-case as to receive and conduct the blast from the wings, at that partA of their rotation where, Without such auxiliary air-passage, they would be comparatively ineffective.

In the drawings- A represents a casing, which may be, externally, of common form. B B are/bearings for the shaft C of a fan, D D D D, which isjournalled eccentrically within the casing A. E represents a curved Wall or partition, extending from head to head of the casing, in a form and position concentric to the shaft C, and suiciently distant therefrom to permit the free passage of the Wings D, in their rotation.I Between the partition E and the external casing A is my auxiliary air-passage, F.

y Operation.

The air is admitted, in the usual manner, through induction-openings, G G, in the centres of the cylinderheads, and discharged tangentially at H. All the air .that is moved by the Wings in passing from z' to j, (fig. 1,) is driven tangentially intogthe auxiliary air-passage F, and by it conveyed freely to the `discharge-port II. I am thus enabled to make the rotary wings 'effective at that part of their rotation where, in fans of ordinary construction, they produce little or no beneficial effect, and this I do without impairing their action as they approach the tangential discharge-port H, which is the part of the rotation where the eifective 'labor of the common rotary fan is performed. l

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-

.The combination 'of the direct tangential dischargeport H, rotary fan D, eccentric lcasing A, and concentric partition E,`all constructed and arranged as herein represented and described, for the purpose specified.

JAMES MITCHELL.

Witnesses:

WALLACE FLETCHER, JOSHUA S. FLETCHER. 

